The present invention relates quality of service (QoS) management of call connections over packet-based networks.
A global network infrastructure for voice services, using a circuit-switching methodology, is supported by Public Switched Telephone and Private Branch Exchange networks. These networks utilize signaling to establish call connections and routing maps at network switches. The ability to signal during call connection set-up provides individual switches with the capability to reject call connection requests when that individual switch can not dedicate the available bandwidth to support a new call connection. Since any switch in a connection path may reject a new call connection request based on available bandwidth limitations, switched voice networks are able to provide guaranteed Quality of Service to established connections. Quality of Service in switched voice networks is guaranteed because the governing precept is that it is preferable to block new call connection attempts rather than allow a new connected call to degrade the performance of established connected calls.
Explosive growth in Internet Protocol (IP) based intranets and the public Internet has generated a large network infrastructure of IP based routers. Recently, this large IP network infrastructure has begun to be utilized as a vehicle for real-time transmission of voice over the Internet, also known as Internet telephony. Each year, Internet telephony captures a greater share of the telephony market. However, unlike the case of switched voice service networks, bandwidth over packet-based networks is not reserved for the real-time transmission of packets, and therefore these networks are subject to the vagaries of packet loss, packet delay, packet arrival out of sequence, and jitter; each of which is a disadvantage when compared to circuit-switched connections established over the Public Switched Telephone Networks and Private Branch Exchanges. Rather, transmission over the Internet and other IP networks is often accomplished via a best effort transmission mode. Even when systems are used to reserve or allocate bandwidth within IP networks, these systems are not foolproof and certain conditions can lead to inadequate bandwidth. Consequently, telephony over IP networks does not currently provide a Quality of Service guarantee for voice and other delay sensitive transmissions.
A Quality of Service (QoS) provision for voice and other delay sensitive call connections established over the Internet and other packet-based networks is achieved by generating a QoS performance parameter value corresponding to the performance of one or more packet-based call connections utilizing common packet network resources, comparing the QoS performance parameter value to an acceptable range of QoS values, and terminating one or more call connections utilizing common packet network resources if the QoS performance parameter value does not fall within the acceptable range of QoS values. The invention leverages the recognition that it is preferable to terminate one or more established call connections to preserve the quality of the remaining call connections, rather than to allow the degradation in the Quality of Service provided to all of the connected calls utilizing common packet network resources.